Method And Apparatus For Controlling Buffer Status Report Messaging

ABSTRACT

An apparatus such as a user equipment user device, smart phone and the like includes a memory device and an associated processor configured to transmit a buffer status report message when a reported buffer size in a last transmitted buffer status report message is satisfied. The apparatus may be configured to store the reported buffer size associated with the last transmitted buffer status report message, and track one or more grants of uplink resource; wherein the reported buffer size associated with the last transmitted buffer status report message is satisfied based on the grants of uplink resource.

FIELD

This invention relates generally to communication networks and, morespecifically but not exclusively, to management of the buffer statusreport messaging in wireless communication networks.

BACKGROUND

Fourth Generation (4G) wireless networks support large numbers ofwireless subscribers running one or more applications wherein traffic ispacketized and transported via IP networks according to multiple networkelements utilizing different transport technologies and appliedquality-of-service (QoS) policies. Contemporary wireless communicationsystems are designed to carry out several types of traffic types asgenerated by several applications. The applications may have verydifferent (and even conflicting) QoS requirements. For instance, someapplications, such as Machine-to-Machine or Instant Messages generate“thin” traffic, which places quite low demand on the user plane, but maybe very bursty and have a significant impact on the control plane. Onthe other hand, some applications, such as video based applications, areless stressful on the control plane but may be very bandwith intensiveon the user plane and subject to time critical constraints.

For example, Long Tenn Evolution (LTE) networks have the capability todeal with such applications having varied and/or conflicting QoSrequirments. FIG. 1 depicts an exemplary wireless communication systemincluding a LTE network. Specifically, FIG. 1 depicts an exemplarywireless communication system 100 that includes a plurality of UserEquipments (UEs) or User Devices (UDs) 102, a Long Term Evolution (LTE)network 110, non-LTE access networks 120, IP networks 130, and amanagement system (MS) 140. The LTE network 110 supports communicationsbetween the UEs 102 and IP networks 130. The non-LTE access networks 120interface with LTE network 110 for enabling UEs associated with non-LTEaccess networks 120 to utilize the LTE network 110 to access IP networks130. The MS 140 is configured for supporting various managementfunctions for LTE network 110.

The UEs 102 are wireless user devices capable of accessing a wirelessnetwork, such as LTE network 110. The UEs 102 are capable of supportingone or more bearer sessions to IP networks 130 via LTE network 110. TheUEs 102 are capable of supporting control signaling in support of thebearer session(s). The UEs 102 each may have one or more identifiersassociated therewith. For example, a UE 102 may have one or more of anInternational Mobile Subscriber Identity (IMSI), an International MobileEquipment Identity (IMEI), and like identifiers or identities associatedtherewith. For example, each of the UEs 102 may be a phone, PDA,computer, or any other wireless user device. Multiple UDs are typicallyactive at all times for each eNodeB (eNB).

The illustrated LTE network 110 is an exemplary LTE network. Theconfiguration and operation of LTE networks will be understood by oneskilled in the art. However, for purposes of completeness, a descriptionof general features of LTE networks is provided herein within thecontext of exemplary wireless communication system 100.

The LTE network 110 includes two eNodeBs 111 ₁ and 111 ₂ (collectively,eNodeBs 111), two Serving Gateways (SGWs) 112 ₁ and 112 ₂ (collectively,SGWs 112), a Packet Data Network (PDN) Gateway (PGW) 113, two MobilityManagement Entities (MMEs) 114 ₁ and 114 ₂ (collectively, MMEs 114), anda Policy and Charging Rules Function (PCRF) 115. The eNodeBs 111 providea radio access interface for UEs 102. The SGWs 112, PGW 113, MMEs 114,and PCRF 115, as well as other components which have been omitted forpurposes of clarity, cooperate to provide an Evolved Packet Core (EPC)network supporting end-to-end service delivery using IP.

The eNodeBs 111 support communications for UEs 102. As depicted in FIG.1, each eNodeB 111 supports a respective plurality of UEs 102. Thecommunication between the eNodeBs 111 and the UEs 102 is supported usingLTE-Uu interfaces associated with each of the UEs 102. The eNodeBs 111may support any functions suitable for being supported by an eNodeB,such as providing an LTE air interface for the UEs 102, performing radioresource management, facilitating communications between UEs 102 andSGWs 112, maintaining mappings between the LTE-Uu interfaces and S1-uinterfaces supported between the eNodeBs 111 and the SGWs 112, and thelike, as well as combinations thereof.

The SGWs 112 support communications for eNodeBs 111. As depicted in FIG.1, SGW 112 ₁ supports communications for eNodeB 111 ₁ and SGW 112 ₂supports communications for eNodeB 111 ₂. The communication between theSGWs 112 and the eNodeBs 111 is supported using respective S1-uinterfaces for example. The S1-u interfaces support per-bearer userplane tunneling and inter-eNodeB path switching during handover. TheS1-u interfaces may use any suitable protocol, e.g., the GPRS TunnelingProtocol-User Place (GTP-U). The SGWs 112 may support any functionssuitable for being supported by an SGW, such as routing and forwardinguser data packets (e.g., facilitating communications between eNodeBs 111and PGW 113, maintaining mappings between the S1-u interfaces and S5/S8interfaces supported between the SGWs 112 and PGWs 113, and the like),functioning as a mobility anchor for UEs during inter-eNodeB handovers,functioning as a mobility anchor between LTE and other 3GPPtechnologies, and the like, as well as combinations thereof.

The PGW 113 supports communications for the SGWs 112. The communicationbetween PGW 113 and SGWs 112 is supported using respective S5/S8interfaces. The S5 interfaces provide functions such as user planetunneling and tunnel management for communications between PGW 113 andSGWs 112, SGW relocation due to UE mobility, and the like. The S8interfaces, which are Public Land Mobile Network (PLMN) variants of theS5 interfaces, provide inter-PLMN interfaces providing user and controlplane connectivity between the SGW in the Visitor PLMN (VPLMN) and thePGW in the Home PLMN (HPLMN). The S5/S8 interfaces may utilize anysuitable protocol (e.g., the GPRS Tunneling Protocol (GTP), Mobile ProxyIP (MPIP), and the like, as well as combinations thereof). The PGW 113facilitates communications between LTE network 110 and IP networks 130via an SGi interface. The PGW 113 may support any functions suitable forbeing supported by an PGW, such as providing packet filtering, providingpolicy enforcement, functioning as a mobility anchor between 3GPP andnon-3GPP technologies, and the like, as well as combinations thereof.

The MMEs 114 provide mobility management functions in support ofmobility of UEs 102. The MMEs 114 support the eNodeBs 111. The MME 114 ₁supports eNodeB 111 ₁ and the MME 114 ₂ supports eNodeB 111 ₂. Thecommunication between MMEs 114 and eNodeBs 111 is supported usingrespective S1-MME interfaces, which provide control plane protocols forcommunication between the MMEs 114 and the eNodeBs 111. The S1-MMEinterfaces may use any suitable protocol or combination of protocol. Forexample, the S1-MME interfaces may use the Radio Access NetworkApplication Part (eRANAP) protocol while using the Stream ControlTransmission Protocol (SCTP) for transport. The MMEs 114 support the SGW112. The MME 114 ₁ supports SGW 112 ₁ and the MME 114 ₂ supports SGW 112₂. The communication between MMEs 114 and SGWs 112 is supported usingrespective S11 interfaces. The MMEs 114 ₁ and 114 ₂ communicate using anS10 interface. The MMEs 114 may support any functions suitable for beingsupported by a MME, such selecting SGWs for UEs at time of initialattachment by the UEs and at time of intra-LTE handovers, providingidle-mode UE tracking and paging procedures, beareractivation/deactivation processes, providing support for Non-AccessStratum (NAS) signaling (e.g., terminating NAS signaling,ciphering/integrity protection for NAS signaling, and the like), lawfulinterception of signaling, and the like, as well as combinationsthereof. The MMEs 114 also may communicate with a Home Subscriber Server(HSS) using an S6a interface for authenticating users (the HSS and theassociated S6a interface are omitted for purposes of clarity).

The PCRF 115 provides dynamic management capabilities by which theservice provider may manage rules related to services provided via LTEnetwork 110 and rules related to charging for services provided via LTEnetwork 110. For example, rules related to services provided via LTEnetwork 110 may include rules for bearer control (e.g., controllingacceptance, rejection, and termination of bearers, controlling QoS forbearers, and the like), service flow control (e.g., controllingacceptance, rejection, and termination of service flows, controlling QoSfor service flows, and the like), and the like, as well as combinationsthereof. For example, rules related to charging for services providedvia LTE network 110 may include rules related to online charging (e.g.,time-based charging, volume-based charging, event-based charging, andthe like, which may depend on factors such as the type of service forwhich charging is being provided), offline charging (e.g., such as forchecking subscriber balances before services are provided and otherassociated functions), and the like, as well as combinations thereof.The PCRF 115 communicates with PGW 113 using a S7 interface. The S7interface supports transfer of rules from PCRF 115 to a Policy andCharging Enforcement Function (PCEF) supported by PGW 113, whichprovides enforcement of the policy and charging rules specified on PCRF115.

As depicted in FIG. 1, elements of LTE network 110 communicate viainterfaces between the elements. The interfaces described with respectto LTE network 110 also may be referred to as sessions. For example, thecommunication between eNodeBs and SGWs is provided via S1-u sessions,communication between SGWs and PGWs is provided via S5/S8 sessions, andso forth, as depicted in FIG. 1 and described herein. The sessions ofLTE network 110 may be referred to more generally as S* sessions. Itwill be appreciated that each session S* that is depicted in FIG. 1represents a communication path between the respective network elementsconnected by the session and, thus, that any suitable underlyingcommunication capabilities may be used to support the session S* betweenthe network elements. For example, a session S* may be supported usinganything from direct hardwired connections to full network connectivity(e.g., where the session S* is transported via one or more networksutilizing nodes, links, protocols, and any other communicationscapabilities for supporting the communication path) and anything inbetween, or any other suitable communications capabilities.

For example, an S1-u session between an eNodeB 111 and an SGW 112 may besupported using an Internet Protocol (IP)/Multiprotocol Label Switching(MPLS) transport capability including mobile backhaul elementsassociated with the eNodeB 111 (e.g., using service aware routers(SARs), service access switches (SAS), and the like) and mobile backhaulelements associated with the SGW 112 (e.g., multi-service edge routersand/or other similar elements), as well as an IP/MPLS aggregationnetwork facilitating communications between the mobile backhaul elementsassociated with the eNodeB 111 and the mobile backhaul elementsassociated with the SGW 112). Similarly, an S1-u session between aneNodeB 111 and an SGW 112 may be supported using an IP routing networkusing a routing protocol (e.g., Open Shortest Path First (OSPF),Intermediate System to Intermediate System (ISIS) and the like). Thetypes of underlying communications capabilities which may be utilized tosupport each of the different types of sessions of LTE network 110 willbe understood by one skilled in the art.

The LTE network 110 supports access to IP networks 130 from non-LTEnetworks 120. The non-LTE networks 120 with which the LTE network 110may interface include 3GPP access networks 121. The 3GPP access networks121 may include any 3GPP access networks suitable for interfacing withLTE network 110 (e.g., 2.5G networks, 3G networks, 3.5G networks, andthe like). For example, the 3GPP access networks 121 may include GlobalSystem for Mobile (GSM) Enhanced Data Rates for GSM Evolution (EDGE)Radio Access Networks (GERANs), Universal Mobile TelecommunicationsSystem (UMTS) Terrestrial Radio Access Networks (UTRANs), or any other3GPP access networks suitable for interfacing with LTE, and the like, aswell as combinations thereof.

The LTE network 110 interfaces with 3GPP access networks 121 via aServing General Packet Radio Service (GPRS) Support Node (SGSN) 122. TheMME 114 ₂ supports control plane functionality for mobility between LTEnetwork 110 and 3GPP access networks 121 using communication with SGSN122 via an S3 interface. For example, the S3 interface enables user andbearer information exchange for 3GPP network access mobility in idleand/or active state. The SGW 112 ₂ supports user plane functionality formobility between LTE network 110 and 3GPP access networks 121 usingcommunication with SGSN 122 via an S4 interface. For example, the S4interface provides the user plane with related control and mobilitysupport between SGSN 122 and SGW 112 ₂.

The non-LTE networks with which the LTE network may interface includenon-3GPP access networks 125. The non-3GPP access networks 125 mayinclude any non-3GPP access networks suitable for interfacing with LTEnetwork 110. For example, the non-3GPP access networks may include 3GPP2access networks (e.g., Code Division Multiple Access 2000 (CDMA 2000)networks and other 3GPP2 access networks), Wireless Local Area Networks(WLANs), and the like). The support for mobility between the LTE network110 and the non-3GPP access networks 125 may be provided using anysuitable interface(s), such as one or more of the S2a interface, the S2binterface, the S2c interface, and the like, as well as combinationsthereof. The S2a interface provides control and mobility support to theuser plane for trusted non-3GPP access to the LTE network. The S2ainterface may provide access for trusted non-3GPP networks using anysuitable protocol(s), such as MPIP, Client Mobile IPv4 Foreign Agent(FA) mode (e.g., for trusted non-3GPP access that does not supportMPIP), and the like, as well as combinations thereof. The S2b interfaceprovides control and mobility support to the user plane for non-trustednon-3GPP access to the LTE network. The S2b interface may be provided aninterface between PGW 113 and an evolved Packet Data Gateway (ePDG)associated with the non-trusted non-3GPP access network. The S2binterface may use any suitable protocol, such as MPIP or any othersuitable protocols. The S2c interface provides control and mobilitysupport to the user plane for providing UEs access to PGW 113 viatrusted and/or non-trusted 3GPP access using one or more protocols basedon Client Mobile IP co-located mode.

The LTE network 110 includes an Evolved Packet System/Solution (EPS). Inone embodiment, the EPS includes EPS nodes (e.g., eNodeBs 111, SGWs 112,PGW 113, MMEs 114, and PCRF 115) and EPS-related interconnectivity(e.g., the S* interfaces, the G* interfaces, and the like). TheEPS-related interfaces may be referred to herein as EPS-related paths.

The IP networks 130 include one or more packet data networks via whichUEs 102 may access content, services, and the like. For example, the IPnetworks 130 include an IP Core network and, optionally, one or moreother IP networks (e.g., IP Multimedia Subsystem (IMS) networks and thelike). The IP networks 130 support bearer and control functions insupport of services provided to UEs 102 via LTE network 110. The IP Corenetwork is capable of providing any functions which may be provided bysuch a core network. The IP Core network is a packet data network viawhich UEs 102 may access content, services, and the like. The IMSnetwork is capable of providing any functions which may be provided byan IMS network.

The MS 140 provides management functions for managing the LTE network110. Management functions of the MS may include discovery (discovery ofinformation about the LTE networks such as configuration information,status/operating information, and connection information which is storedin a discovery database), correlation (correlation of discovered networkelements to specific customer traffic flows supporting customer serviceswhich information is stored in a paths database), analysis of networkinformation, auditing, trace for providing trace functionality, andfairness management for providing enforcement functionality.

The MS 140 may communicate with LTE network 110 in any suitable manner.In one embodiment, for example, MS 140 may communicate with LTE network110 via a communication path 141 which does not traverse IP networknetworks 130. In one embodiment, for example, MS 140 may communicatewith LTE network 110 via a communication path 142 which then passes viaIP network networks 130. The communication paths 141 and 142 may beimplemented using any suitable communications capabilities.

The MS 140 is adapted to receive information from LTE network 110 (e.g.,discovery information adapted for use in determining the topology of LTEnetwork, results of test initiated by MS 140 to LTE network 110, and thelike, as well as any other information which may be received by MS 140from LTE network 110 in support of the management functions performed byMS 140). Similarly, for example, MS 140 is adapted to transmitinformation to LTE network 110 (e.g., discovery requests for discoveringinformation adapted for use by MS 140 in determining the topology of LTEnetwork, audits request for auditing portions of LTE network 110, andthe like, as well as any other information which may be transmitted byMS 140 to LTE network 110 in support of the management functionsperformed by MS 140).

In dealing with applications, a conventional LTE network makes use ofBuffer Status Report (BSR) messages. The Buffer Status reportingprocedure is used to provide the serving eNB with information about theamount of data available for transmission in the UpLink (UL) buffers ofthe UE. Radio Resource Control (RRC) controls BSR reporting byconfiguring two timers, a periodic BSR timer (e.g., “periodicBSR-Timer”)which indicates the periodic timing of a BSR message and a retransmitBSR timer (e.g., “retxBSR-Timer”) which indicates a retransmission waitperiod for retransmission of a BSR message upon transmission of the BSRmessage. Optionally, the RRC may also signal, for each logical channel,a logical channel group indicator (e.g., “logicalChannelGroup”) whichallocates the logical channel to a Logical Channel Group (LCG). For theBuffer Status reporting procedure, the UE considers all radio bearerswhich are not suspended and may consider radio bearers which aresuspended. In conjunction with such BSR messaging, the network attemptsto provide a desired level of Quality of Service (QoS).

FIG. 2 represents an example flowchart illustrating the default LTEprotocol 200 for sending Buffer Status Report (BSR) messages from a UserEquipment (UE). At step 210, the UE is known to have an empty buffer. Anempty buffer indicates that there is no data available for transmissionin the UpLink (UL) buffers of the UE. At step 212, after packet arrivalfrom the upper layer (i.e., application layer), the UE sends a regularBSR message which indicates the total buffer size to an eNB. The UE alsostarts the periodic BSR timer and starts the retransmit BSR timer. TheUE then proceeds to wait for a grant message at step 214.

While waiting for the grant, if the retransmit BSR timer times outbefore receipt of the grant, the UE loops back to step 212 and againsends a regular BSR message, and restarts the periodic BSR timer and theretransmit BSR timer. Thus, the illustrated procedure will wait for agrant message for up to a period of time equivalent to the value of theretransmit BSR timer before resending a regular BSR message.

While waiting for the grant, if the grant is received before theretransmit BSR timer times out, the UE proceeds to step 216 where it isdetermined whether the buffer size is greater than the grant size. Thatis; it is determined whether the amount of data available fortransmission in the UL buffers of the UE is larger than the grant size.

If the buffer size is not greater than the grant size, at step 218 theUE transmits data with the data size equal to the buffer size, andterminates the periodic BSR timer and the retransmit BSR timer. That is,the UE will transmit all data remaining in the UL buffers and end BSRtiming. After these activities, the UE loops back to step 210 at whichpoint the buffer is once again known to be empty.

If the buffer size is greater than the grant size, the UE determineswhether the periodic BSR timer has expired at step 220. The value of theperiodic BSR timer indicates a period of time to wait betweentransmissions of BSR messages. If the periodic BSR timer has notexpired, the UE transmits a data message with data size equivalent tothe grant size at step 222 and then returns to step 214 to await anothergrant so as to be permitted to transmit additional portion(s) of thedata remaining in the UL buffers at the UE. If the periodic BSR timerhas expired, at step 224, the UE prepares a periodic BSR message toreport the buffer size as the buffer size minus the difference of thegrant size minus the BSR message size, transmits a data message withdata equivalent to the grant size minus the BSR message size, andrestarts the periodic BSR timer and the retransmit BSR timer. Thus,after receiving a grant that is not larger than the buffer size (i.e.,amount of data available for transmission in the UL buffer(s) of the UE)and expiration of the periodic BSR timer, the illustrated proceduresends a periodic BSR message and a portion of the data in the ULbuffer(s) of the UE. The UE then returns to step 214 to await a grant tobe able to transmit additional portion(s) of the data remaining in theUL buffers at the UE.

Additional description for the BSR is found in the 3GPP document TS36.321 and the potential values for periodic BST timer (e.g.,“periodicBSR-Timer”) and retransmit BSR timer (e.g., “retxBSR-Timer”)are provided in the RRC document, namely 3GPP TS 36.331 both of whichare know to those skilled in the art of the invention and hereinincorporated by reference. MAC-MainConfig topic of section 6.3.2 in 3GPPTS 36.331 lists those values for both timers. Some default values aresuggested in section 9.2.2 of the same document. The periodic BSR timer“periodicBSR-Timer” (default=infinity) is optional and the values aresf5, sf10, sf16, sf20, sf32, sf40, sf64, sf80, sf128, sf160, sf320,sf640, sf1280, sf2560, infinity and spare1 (“sf5” means subframe 5 andit is equivalent to 5 msec; “sf10” means subframe 10 and it isequivalent to 10 msec, etc.). The retransmit BSR timer “retxBSR-Timer”(default=sf2560) values are sf320, sf640, sf1280, sf2560, sf5120,sf10240, spare2 and spare1.

FIG. 3 is an example communication flow illustrating UE-eNB packettransmissions according to the protocol for sending BSR messagesdetailed in FIG. 2. In the illustrated example of FIG. 3, the periodicBSR timer is set to five (5) subframes and the retransmit BSR timer isset two-thousand five-hundred sixty (2560) subframes. Time, denoted bytimes instances numbered T99, T100, . . . T113 runs from the top tobottom of FIG. 3. While both periodic BSR timer and the retransmit BSRtimer are utilized, activity associated with the expiration of theretransmit BSR timer is not in action/invoked in the illustrated exampleof FIG. 3.

At time T99, fifteen hundred (1500) bytes are placed in the UL buffer/sof the UE. At time T100, a regular BSR message is transmitted from theUE to the eNB. The BSR message is characterized as regular since it isthe initial BSR message. The BSR message indicates that there arefifteen hundred (1500) bytes are in the buffer of the UE (i.e., fifteenhundred (1500) bytes available for transmission in the UL buffers of theUE). At time T101, an additional three hundred (300) bytes are placed inthe UL buffers of the UE. At time T102, the eNB transmits a first grantmessage to the UE; the UE receives from the eNB the first grant for fivehundred (500) bytes. The buffer size being greater than the grant sizeand the periodic BSR timer not yet having expired (FIG. 2: 216, 220), attime T103, the UE transmits a first data message of five hundred (500)bytes (FIG. 2: 222). At time T105, while waiting for the next grant(FIG. 2: 214), the periodic BSR timer has expired and the UE is ready toprepare a periodic BSR message (P_BSR). The periodic timer expires onT105 since the timer value is 5 subframes/5 ms.

At time T106, the UE receives from the eNB a second grant for fivehundred (500) bytes. Buffer size is now thirteen hundred bytes (1500 atstart+300 added−500 transmitted=1300). The buffer size being greaterthan the grant size and the periodic BSR timer having expired (FIG. 2:216, 220), at time T107, the UE prepares and transmits a periodic BSRmessage data message and a second data message (FIG. 2: 224). Theperiodic BSR message transmitted reports the buffer size as eighthundred ten (810) bytes, which is the buffer size (1300 bytes) minus thedifference of the grant size (500 bytes) minus the BSR message size(e.g., 10 bytes). The transmitted data message has a data size equal tofour hundred ninety (490) bytes, which is a size equivalent to the grantsize (500 bytes) minus the BSR message size (e.g., 10 bytes).

At time T108, the eNB transmits a third grant to the UE; the UE receivesfrom the eNB the third grant for eight hundred ten (810) bytes. Thebuffer size not being greater than the grant size (FIG. 2: 216), at timeT110, the UE transmits a third data message with a data size equivalentto the grant of eight hundred ten (810) (FIG. 2: 218). The UL buffers ofthe UE are now empty and the illustrative example ends.

SUMMARY

Apparatus and methodology are provided for transmitting a BSR message assoon as the reported buffer size in the last BSR message is satisfied.The methodology involves tracking the total grant size since the lastBSR transmission. In this manner, the embodiments provided are able torespond to the specific needs of applications and, as such, packetaccess delay and jitter will be reduced regardless of application type.

In one embodiment, an apparatus includes a memory device and anassociated processor with the processor configured to transmit a bufferstatus report message when a reported buffer size in a last transmittedbuffer status report message is satisfied. In one embodiment, theprocessor of the apparatus is configured to store the reported buffersize associated with the last transmitted buffer status report message,and track one or more grants of uplink resource; wherein the reportedbuffer size associated with the last transmitted buffer status reportmessage is satisfied based on the grants of uplink resource. In oneembodiment, the processor of the apparatus may be configured to transmitthe last transmitted buffer status report message.

In another embodiment, the processor of the apparatus is configured toreceive one or more grant messages, the one or more grant messages eachindicating a corresponding grant size of the uplink resource; andaccumulate a total grant size based on the corresponding grant size ofthe one or more grant messages. In one embodiment, the processor of theapparatus is configured to determine that the reported buffer sizeassociated with the last transmitted buffer status report message issatisfied if the total grant size is greater than or equal to thereported buffer size associated with the last transmitted buffer statusreport message. In another embodiment, the processor of the apparatus isconfigured to determine that the reported buffer size associated withthe last transmitted buffer status report message is satisfied whenbuffer size is greater than grant size of a first of the one or moregrants of uplink resource, a periodic buffer status report timer has notexpired, and a total grant size of the one or more grants of uplinkresource is greater than or equal to the reported buffer size associatedwith the last transmitted buffer status report message.

The apparatus may be a user equipment, user device, smart phone, mobilestation and the like. In one embodiment, the processor of the apparatusmay be configured to transmit a data message in response to the one ormore grants of uplink resource. In a further embodiment, the processorof the apparatus is configured to adjust a size of the data message toaccount for transmission of the buffer status report message within asame grant of uplink resource

In one embodiment, the processor of the apparatus is configured totransmit another buffer status report message periodically. In anotherembodiment, the processor of the apparatus is configured to transmitanother buffer status report message in response to the one or moregrants of uplink resource after expiry of a periodic timer.

An example method embodiment includes storing a reported buffer sizeassociated with a last transmitted buffer status report message,tracking one or more grants of uplink resource, and transmitting abuffer status report message when the reported buffer size associatedwith the last transmitted buffer status report message is satisfiedbased on the one or more grants of uplink resource.

In one embodiment, the method further includes transmitting the lasttransmitted buffer status report message. In another embodiment,tracking one or more grants of uplink resource includes receiving one ormore grant messages, the one or more grant messages each indicating acorresponding grant size of the uplink resource, and accumulating atotal grant size based on the corresponding grant size of the one ormore grant messages.

In one embodiment, the method includes determining the reported buffersize associated with the last transmitted buffer status report messageis satisfied if the total grant size is greater than or equal to thereported buffer size associated with the last transmitted buffer statusreport message. In one embodiment, the method includes determining ifthe reported buffer size associated with the last transmitted bufferstatus report message is satisfied when buffer size is greater thangrant size of a first of the one or more grants of uplink resource, aperiodic buffer status report timer has not expired and a total grantsize of the one or more grants of uplink resource is greater than orequal to the reported buffer size associated with the last transmittedbuffer status report message.

The method may be performed by a user equipment, user device, smartphone, mobile station and the like. In one embodiment, the methodincludes transmitting a data message in response to the one or moregrants of uplink resource. Transmitting the data message may includetransmitting the data message with a size of the data message adjustedto account for the transmitting of the buffer status report messagewithin a same grant of uplink resource in another embodiment.

In one embodiment, the method includes transmitting another bufferstatus report message periodically. A further embodiment includestransmitting another buffer status report message in response to thegrants of uplink resource after expiry of a periodic timer.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings. The Figures represent non-limiting, example embodiments asdescribed herein.

FIG. 1 depicts an exemplary wireless communication system including aLTE network;

FIG. 2 represents an example flow chart illustrating the default LTEprotocol for sending Buffer Status Report (BSR) messages;

FIG. 3 is an example communication flow illustrating UE-eNB packettransmissions according to the protocol for sending BSR messagesdetailed in FIG. 2;

FIG. 4 is an example communication flow illustrating UE-eNB packettransmissions with packet delay performance degradation caused accordingto the default protocol for sending BSR messages detailed in FIG. 2.

FIG. 5 is an example communication flow illustrating UE-eNB packettransmissions with signaling overhead increasing according to thedefault protocol for sending BSR messages detailed in FIG. 2;

FIG. 6 represents an example flow chart illustrating an enhanced LTEprotocol for sending Buffer Status Report (BSR) messages;

FIG. 7 is an example communication flow illustrating UE-eNB packettransmissions according to the protocol for sending BSR messagesdetailed in FIG. 6;

FIG. 8 represents another example flow chart illustrating an enhancedLTE protocol for sending Buffer Status Report (BSR) messages;

FIG. 9 depicts a high-level block diagram of a computer suitable for usein performing the functions described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures.

DETAILED DESCRIPTION

Various example embodiments will now be described more fully withreference to the accompanying drawings in which some example embodimentsare illustrated. Accordingly, while example embodiments are capable ofvarious modifications and alternative forms, embodiments thereof areshown by way of example in the drawings and will herein be described indetail. It should be understood, however, that there is no intent tolimit example embodiments to the particular forms disclosed, but on thecontrary, example embodiments are to cover all modifications,equivalents, and alternatives falling within the scope of the claims.Like numbers refer to like elements throughout the description of thefigures.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. References to ‘one embodiment’ or ‘an embodiment’ need notnecessarily refer to a single embodiment; that is an embodiment need notinclude all features referring to as being in ‘an embodiment.’ As usedherein, the singular forms “a,” “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, integers, steps, operations, elementsand/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components and/or groups thereof.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedsubstantially concurrently or may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Portions of example embodiments and corresponding detailed descriptionare presented in terms of software, or algorithms and symbolicrepresentations of operation on data bits within a computer memory.These descriptions and representations are the ones by which those ofordinary skill in the art effectively convey the substance of their workto others of ordinary skill in the art. An algorithm, as the term isused here, and as it is used generally, is conceived to be aself-consistent sequence of steps leading to a desired result. The stepsare those requiring physical manipulations of physical quantities.Usually, though not necessarily, these quantities take the form ofoptical, electrical, or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like.

In the following description, illustrative embodiments will be describedwith reference to acts and symbolic representations of operations (e.g.,in the form of flowcharts) that may be implemented as program modules orfunctional processes including routines, programs, objects, components,data structures, etc., that perform particular tasks or implementparticular abstract data types and may be implemented using existinghardware at existing network elements or control nodes (e.g., ascheduler located at a cell site, base station or Node B, a userequipment device). Such existing hardware may include one or moreCentral Processing Units (CPUs), digital signal processors (DSPs),application-specific-integrated-circuits, field programmable gate arrays(FPGAs) computers or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, or as is apparent from the discussion,terms such as “processing” or “computing” or “calculating” or“determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

Note also that the software implemented aspects of example embodimentsmay be encoded on some form of tangible (or recording) storage medium.The tangible storage medium may be magnetic (e.g., a floppy disk or ahard drive) or optical (e.g., a compact disk read only memory, or “CDROM”), and may be read only or random access. Example embodiments arenot limited by these aspects of any given implementation.

As used herein, the term “user equipment” (UE) may be synonymous to userequipment, user device, user equipment device, a mobile user, mobilestation, mobile terminal, user, subscriber, smart phone, wirelessterminal and/or remote station and may describe a remote user ofwireless resources in a wireless communication network.

When utilizing BSR messaging according to LTE standards, performancedegradation may occur when the periodic BSR timer has not expired yetbut the total granted size is equal to or more than the reported size inthe last sent BSR message. In such cases, it is very possible toencounter scenarios where the UE (e.g., the LTE terminal) buffer keepsincreasing due to new packets created by applications on the UE (e.g.,video, picture, document, etc.) but, the UE is not be able to sendanother BSR message until the BSR retransmission timer expires. As aresult, the eNB (this is the LTE Base Station) does not have anyknowledge of the UE buffer conditions and does not allocate anyresources until it receives a new BSR request. Eventually, resourceswill be allocated after the BSR retransmission timer expires and a BSRmessage is forwarded by the UE to the eNB. However, the delay untilexpiration of the BSR retransmission timer may result in increasedaccess delay and jitter beyond what can be tolerated per application.For instance, the VoIP packet can only tolerate a delay budget which istypically 200 ms to 250 ms end-to-end; beyond this delay threshold VoIPpackets may be dropped resulting in a reduced quality of service orquality of experience.

FIG. 4 is an example communication flow illustrating UE-eNB packettransmissions with packet delay performance degradation caused accordingto the default protocol for sending BSR messages detailed in FIG. 2. Inthe illustrated example of FIG. 4, the periodic BSR timer is set to ten(10) subframes and the retransmit BSR timer is set two-thousandfive-hundred sixty (2560) subframes. Time, denoted by times instancesnumbered T99, T100, . . . T2665 runs from the top to bottom of FIG. 4.While both periodic BSR timer and the retransmit BSR timer are utilized,activity associated with the expiration of the retransmit BSR timer isin action/invoked in the illustrated example.

Referring to FIG. 4, at time T99, fifteen hundred (1500) bytes are placein the UL buffer/s of the UE. At time T100, a regular BSR message istransmitted from the UE to the eNB. The BSR message is characterized asregular since it is the initial BSR message. The BSR message indicatesthat there are fifteen hundred (1500) bytes are in the buffer of the UE(i.e., fifteen hundred (1500) bytes available for transmission in the ULbuffers of the UE). At time T102, an additional three hundred (300)bytes are placed in the UL buffers of the UE so that there are noweighteen hundred bytes (1800) available for transmission. At time T104,the eNB transmits a first grant to the UE; the UE receives from the eNBthe first grant for five hundred (500) bytes. The buffer size beinggreater than the grant size and the periodic BSR timer not yet havingexpired (FIG. 2: 216, 220), at time T106, the UE transmits a first datamessage of five hundred (500) bytes (FIG. 2: 222).

At time T107, the eNB transmits a second grant to the UE; the UEreceives from the eNB the second grant for five hundred (500) bytes.Once again, the buffer size being greater than the grant size and theperiodic BSR timer not yet having expired (FIG. 2: 216, 220), at timeT108, the UE transmits a second data message of five hundred (500) bytes(FIG. 2: 222).

At time T109, the eNB transmits a third grant to the UE; the UE receivesfrom the eNB the third grant for five hundred (500) bytes. The buffersize being greater than the grant size and the periodic BSR timer notyet having expired (FIG. 2: 216, 220), at time T110, the UE transmits athird data message of five hundred (500) bytes. Thereafter, the periodicBSR timer expires and the UE is ready to prepare a periodic BSR message(P_BSR). At this time, three hundred (300) bytes remain in the UEbuffer. However, the UE has to wait (FIG. 2: 214) until the retransmitBSR timer expires before transmitting any additional data. At thispoint, the UE can not send any BSR messages for the following reasons:

The eNB has already granted the fifteen hundred (1500) bytes requestedby the UE; therefore, the eNB would not send any additional grantmessage(s) at this point in time;

While the periodic BSR timer has expired and the UE is ready to send aperiodic BSR message for the remaining three hundred (300) bytes, the UEhas to wait until it is granted permission to send a BSR message again;

A regular BSR message can not be sent because the retransmit BSR timeris still running and must first expire before a regular BSR message issent.

During this interval until the retransmit BSR timer expires, packetdelay and jitter performance degradation occur.

At time T2660, the retransmit BSR timer expires and accordingly, at timeT2661 a regular BSR message is transmitted from the UE to the eNB toindicate that there are three hundred (300) bytes in the UL buffer(s) ofthe UE. At time T2663, the eNB transmits a first grant to the UE; the UEreceives from the eNB the first grant for three hundred (300) bytes. Thebuffer size not being greater than the grant size (FIG. 2: 216), at timeT2665, the UE transmits a first data message of three hundred (300)bytes (FIG. 2: 218). (Here in this example illustration, first, second,third denote the sequential number of the grant message or data messagein relation to a corresponding regular BSR message.)

In addition, it is noted that a periodic BSR message (i.e., P_BSR)cannot be inserted in the resourse granted through the third grant whichhas been received before the periodic BSR timer has expired. A P_BSR cannot follow after a grant message which is received before the periodicBSR timer expires. This is so because when the third grant is received,the Media Access Control (MAC) Protocol Data Unit (MPDU) packet iscreated for the transmission without considering insertion of periodicBSR message since the corresponding timer has not expired yet.

A remedy for the above problem of packet delay performance degradationis to set the BSR transmission and BSR retransmission timers such thatthe packet delay problem is minimized. The periodic BSR timer (e.g.,“periodicBSR-Timer”) can be set to a very small value so that the UEwill inform the network in a more timely manner regarding the UE'scurrent status. This action would allow the network to be aware of thepotential UE data backlog and to take appropriate actions when possible.However, a drawback of this small periodic BSR timer value solution isthat with a small timer value, the UE will generate far many moreperiodic BSR transmit requests, which in turn will result in signalingoverhead increase (as represented in FIG. 5). Since the control channelsare the bottleneck for thin applications, increasing the signalingoverhead further is not be an acceptable solution.

FIG. 5 is an example communication flow illustrating UE-eNB packettransmissions with signaling overhead increasing according to thedefault protocol for sending BSR messages detailed in FIG. 2 whenperiodic BSR timer value is decreased. In the illustrated example ofFIG. 5, the periodic BSR timer is set to five (5) subframes and theretransmit BSR timer is set two-thousand five-hundred sixty (2560)subframes. Time, denoted by times instances numbered T99, T100, . . .T114 runs from the top to bottom of FIG. 5. While both periodic BSRtimer and the retransmit BSR timer are utilized, activity associatedwith the expiration of the retransmit BSR timer is not in action/invokedin the illustrated example.

At time T99, ten thousand (10000) bytes are now in the buffer of the UE.At time T100, a regular BSR message is transmitted from the UE to theeNB. The BSR message is characterized as regular since it is the initialBSR message. The BSR message indicates that there are ten thousand(10000) bytes are in the buffer of the UE (i.e., ten thousand (10000)bytes available for transmission in the UL buffer(s) of the UE). At timeT101, an additional one thousand (1000) bytes are placed in the ULbuffers of the UE so that there are now eleven thousand bytes (11000)available for transmission. At time T102, the eNB transmits a firstgrant to the UE; the UE receives from the eNB the first grant for onethousand (1000) bytes. The buffer size being greater than the grant sizeand the periodic BSR timer not yet having expired (FIG. 2: 216, 220), attime T106, the UE transmits a first data message of one thousand (1000)bytes (FIG. 2: 222).

At time T105, the periodic BSR timer expires and the UE is ready toprepare a periodic BSR message.

At time T106, the UE receives from the eNB a second grant for onethousand (1000) bytes. Buffer size is now ten thousand bytes (10000initially+1000 added−1000 transmitted=10000). The buffer size beinggreater than the grant size and the periodic BSR timer having expired(FIG. 2: 216, 220), at time T107, the UE prepares and transmits aperiodic BSR message and a second data message. The periodic BSR messagetransmitted reports the buffer size as nine thousand ten (9010) bytes,which is the buffer size (10000 bytes) minus the difference of the grantsize (1000 bytes) minus the BSR message size (e.g. 10 bytes). Thetransmitted a data message has a data size equal to nine hundred ninety(990) bytes, which is a size equivalent to the grant size (1000 bytes)minus the BSR message size (10 bytes).

At time T108, the eNB transmits a third grant to the UE; the UE receivesfrom the eNB the third grant for one thousand (1000) bytes. The buffersize being greater than the grant size and the periodic BSR timer havingexpired (FIG. 2: 216, 220), at time T110, the UE transmits a third datamessage of one thousand (1000) bytes (FIG. 2: 222).

At time T110, periodic BSR timer has expired and so the UE is ready toprepare a periodic BSR message data message. At time T113, the UEreceives from the eNB a fourth grant for one thousand (1000) bytes.Buffer size is now eight thousand ten bytes (9010 at last P_BSR−1000transmitted=8010). The buffer size being greater than the grant size andthe periodic BSR timer having expired (FIG. 2: 216, 220), at time T114,the UE prepares and transmits a periodic BSR message data message and afourth data message. The periodic BSR message transmitted reports thebuffer size as seven thousand twenty (7020) bytes, which is the buffersize (8010 bytes) minus the difference of the grant size (1000 bytes)minus the BSR message size (e.g. 10 bytes). The transmitted data messagehas a data size equal to nine hundred ninety (990) bytes, which is asize equivalent to the grant size (1000 bytes) minus the BSR messagesize (10 bytes).

Note that when the periodic BSR timer is expired and resource isgranted, a periodic BSR message is transmitted. The frequency oftransmitting the periodic BSR message increses with a smaller durationperiodic BSR timer, resulting in increased signaling overhead. Fromcomparision of FIGS. 4 and 5, the increase in signaling overhead may bevisualized.

In addition to the signaling overhead increase, the remedy of decreasingperiodic BSR timer length may still fail to overcome the packet delayand jitter performance degradation since the scenario described in FIG.4 still may occur with the smallest periodic BSR timer (i.e., 5 msec)specified in 3GPP document (TS 36.331). Further, the retransmit BSRtimer (e.g., “retxBSR-Timer”) being set to the minimum value specifiedby 3GPP will not solve the problem either, as the inter-packet delayaccess can be still higher than 320 msec which is not acceptable for allapplications. Moreover, choosing any set of timer values for theperiodic BSR timer and the retransmit BSR timer (e.g.,“periodicBSR-Timer”=value X and “retxBSR-Timer”=value Y) fails tooptimize the access delay of all applications.

Apparatus and methodology are provided that escape from the waitingprocess (FIG. 2: 214) as soon as the reported buffer size in the lastBSR message is satisfied. The methodology involves tracking the totalgrant size since the last BSR transmission. Accordingly, the providedmethodology is able to respond to the specific needs of applicationsand, as such, packet access delay and jitter will be reduced regardlessof application type.

FIG. 6 represents an example flowchart illustrating an enhanced protocol600 for sending Buffer Status Report (BSR) messages from a UE. At step610, the UE is known to have an empty buffer. An empty buffer indicatesthat there is no data available for transmission in the UL buffers ofthe UE. At step 612, after packet arrival from the upper layer (e.g.,application layer), the UE sends to an eNB a regular BSR message whichindicates the total buffer size, starts the periodic BSR timer andstarts the retransmit BSR timer. The UE then proceeds to wait for agrant message at step 614.

While waiting for a grant message, if the retransmit BSR timer expiresbefore receipt of the grant, the UE loops back to step 612 and againsends a regular BSR message and restarts the periodic BSR timer and theretransmit BSR timer. Thus, the enhanced procedure will wait for a grantmessage for up to a period of time equivalent to the value of theretransmit BSR timer before resending a regular BSR message.

While waiting for a grant message, if the grant is received before theretransmit BSR timer expires, the UE proceeds to step 616 where it isdetermined whether the buffer size is greater than the grant size. Thatis; it is determined whether the amount of data available fortransmission in the UL buffers of the UE is larger than the grant size.

If the buffer size is not greater than the grant size, at step 618 theUE transmits data with the data size equal to the buffer size, andterminates the periodic BSR timer and the retransmit BSR timer. That is,the UE will transmit all data remaining in the UL buffers and end BSRtiming. After these activities, the UE loops back to step 610 at whichpoint the buffer is once again known to be empty.

If the buffer size is greater than the grant size, the UE determineswhether the periodic BSR timer has expired at step 620. The value of theperiodic BSR timer indicates a period of time to wait betweentransmissions of BSR messages. If the periodic BSR timer has notexpired, the UE prepares to transmit a data message with data sizeequivalent to the grant size at step 622 and proceeds to step 626 todetermine whether the total grant size since the last BSR is greaterthan or equal to the last BSR size.

If the total grant size since the last BSR is not greater than or equalto the last BSR size then the prepared date message is transmitted andthe procees proceeds to step 614 to await another grant of permission totransmit additional portion(s) of the date remaining in the UL buffer atthe UE.

If the total grant size since the last BSR is greater than or equal tothe last BSR size then the process proceeds to step 612 to send aregular BSR message indicating the buffer size and restart the periodicBSR timer and the retransmit BSR timer. Adjustment in the size of theprepared data message is also made to account for the transmission of aBSR message within this same grant.

Returning to step 620, if the periodic BSR timer has expired, at step624, the UE prepares a periodic BSR message to report the buffer size asthe buffer size minus the difference of the grant size minus the BSRmessage size, transmits a data message with data equivalent to the grantsize minus the BSR message size, and restarts the periodic BSR timer andthe retransmit BSR timer. Thus, after receiving a grant that is notlarger than the buffer size (i.e., the amount of date available fortransmission in the UL bufers of the UE) and expiration of the periodicBSR timer, the illustrated procedure send a periodic BSR message and aportion of the data in the UL buffers of the UE to the eNB. The UE thenreturns to step 614 to await a grant to be able to transmit additionalportion/s of the data remaining in the UL buffers at the UE.

Thus, as soon as the total grant size is equal to or more than thereported buffer size, a UE according to the methodology herein is ableto send a regular BSR message without waiting for the retransmit BSRtimer to expire. This robust mechanism enables the reduction ofcongestion in wireless networks and increases the user quality ofexperience (in particular by reducing application access and jitter)without greatly increasing signaling overhead as comparing to priorsolutions for reducing congestion causes by BSR messaging.

FIG. 7 is an example communication flow illustrating UE-eNB packettransmissions according to the enhanced protocol for sending BSRmessages detailed in FIG. 6. In the illustrated example of FIG. 6, theperiodic BSR timer is set to ten (10) subframes and the retransmit BSRtimer is set two-thousand five-hundred sixty (2560) subframes. Time,denoted by times instances numbered T99, T100, . . . T114 runs from thetop to bottom of FIG. 7. While both periodic BSR timer and theretransmit BSR timer are utilized, activity associated with theexpiration of the retransmit BSR timer is not in action/invoked in theillustrated example

At time T99, fifteen hundred (1500) bytes are now in the buffer of theUE. At time T100, a regular BSR message is transmitted from the UE tothe eNB. The BSR message is characterized as regular since it is theinitial BSR message. The BSR message indicates that there are fifteenhundred (1500) bytes are in the buffer of the UE (i.e., fifteen hundred(1500) bytes available for transmission in the UL buffers of the UE). Attime T102, an additional three hundred (300) bytes are placed in the ULbuffers of the UE. At time T104, the eNB transmits a first grant messageto the UE; the UE receives from the eNB the first grant for five hundred(500) bytes. The buffer size being greater than the grant size and theperiodic BSR timer not yet having expired (FIG. 6: 616, 620), at timeT106, the UE transmits a first data message of five hundred (500) bytes(FIG. 6: 622). At this point in time, the total grant size since thelast BSR (500 bytes) is not greater than or equal to the last BSR size(1500 bytes) so the UE waits for the next grant (FIG. 6: 626, 614).

At time T107, the eNB transmits a second grant to the UE; the UEreceives from the eNB the second grant for five hundred (500) bytes. Thebuffer size being greater than the grant size and the periodic BSR timernot yet having expired (FIG. 6: 616, 620), at time T108, the UEtransmits a second data message of five hundred (500) bytes (FIG. 6:622). At this point, the total grant size since the last BSR (1000bytes=first grant 500 bytes+second grant 500 bytes) is not greater thanor equal to the last BSR size (1500 bytes) so the UE waits for the nextgrant (FIG. 6: 626, 614).

At time T109, the eNB transmits a third grant to the UE; the UE receivesfrom the eNB the third grant for five hundred (500) bytes.

At this point, the total grant size since the last BSR (1500 bytes) isgreater than or equal to the last BSR size (1500 bytes). Therefore, aregular BSR can be sent (FIG. 6: 626, 612).

A regular BSR message can be sent without waiting for the retransmisisontimer expiration so that performance degradation is minimized and/oravoided. Adjustment in the size of the prepared data message (FIG. 6:622) is made to account for the transmission of a BSR message withinthis same grant. Accordingly, the size of the data message transmittedat T110 is adjusted for the size of the BSR message transmission (Datamessage=grant size (500 bytes)−BSR message size (10 bytes)=490 bytes)and the BSR message reflects the remaining size of the UL buffers (390bytes=UL buffer size (800 bytes)−data message size (490 bytes).

At time T112, the eNB transmits a fourth grant to the UE; the UEreceives from the eNB the fourth grant for three hundred ten (310)bytes. The buffer size not being greater than the grant size (FIG. 6:616), at time T114, the UE transmits a fourth data message with a datasize equivalent to the grant of three hundred ten (310) bytes (FIG. 6:618).

FIG. 8 represents an example flowchart illustrating an enhanced protocol800 for sending Buffer Status Report (BSR) messages from a UE. At step810, the UE is known to have an empty buffer. An empty buffer indicatesthat there is no data available for transmission in the UL buffers ofthe UE. At step 812, after packet arrival from the upper layer (e.g.,application layer), the UE sends to an eNB a regular BSR message whichindicates the total buffer size, starts the periodic BSR timer andstarts the retransmit BSR timer. The UE then waits for a grant messageat step 814.

While waiting for a grant message, if the retransmit BSR timer expiresbefore receipt of the grant, the UE loops back to step 812 and againsends a regular BSR message and restarts the periodic BSR timer and theretransmit BSR timer. Thus, the enhanced procedure will wait for a grantmessage for up to a period of time equivalent to the value of theretransmit BSR timer before resending a regular BSR message.

While waiting for a grant message, if the grant is received before theretransmit BSR timer expires, the UE proceeds to step 816 where it isdetermined whether the buffer size is greater than the grant size. Thatis; it is determined whether the amount of data available fortransmission in the UL buffers of the UE is larger than the grant size.

If the buffer size is not greater than the grant size, at step 818 theUE transmits data with the data size equal to the buffer size, andterminates the periodic BSR timer and the retransmit BSR timer. That is,the UE will transmit all data remaining in the UL buffers and end BSRtiming. After these activities, the UE loops back to step 810 at whichpoint the buffer is once again known to be empty.

If the buffer size is greater than the grant size, the UE determineswhether the periodic BSR timer has expired at step 820. The value of theperiodic BSR timer indicates a period of time to wait betweentransmissions of BSR messages. If the periodic BSR timer has notexpired, the methodology proceeds to step 822 to determine whether thetotal grant size since the last BSR is greater than or equal to the lastBSR size.

If the total grant size since the last BSR is not greater than or equalto the last BSR size then the UE prepares to transmit a data messagewith data size equivalent to the grant size at step 824 and proceeds tostep 814 to await another grant of permission to transmit additionalportions of the date remaining in the UL buffer at the UE.

If the total grant size since the last BSR is greater than or equal tothe last BSR size then at step 826 the UE prepares and sends a regularBSR message to report the buffer size as the buffer size minus thedifference of the grant size minus the BSR message size, transmits adata message with data equivalent to the grant size minus the BSRmessage size, and restarts the periodic BSR timer and the retransmit BSRtimer. The data message and BSR message utilize the grant. The methodthen proceeds to step 814 to await a grant to be able to transmitadditional portion/s of the data remaining in the UL buffers at the UE.

Returning to step 820, if the periodic BSR timer has expired, at step824, the UE prepares a periodic BSR message to report the buffer size asthe buffer size minus the difference of the grant size minus the BSRmessage size, transmits a data message with data equivalent to the grantsize minus the BSR message size, and restarts the periodic BSR timer andthe retransmit BSR timer. Thus, after receiving a grant that is notlarger than the buffer size (i.e., the amount of date available fortransmission in the UL bufers of the UE) and expiration of the periodicBSR timer, the illustrated procedure transmits/sends a periodic BSRmessage and a porton of the data in the UL buffers of the UE to the eNB.The UE then returns to step 814 to await a grant to be able to transmitadditional portion's of the data remaining in the UL buffers at the UE.

Thus, as soon as the total grant size is equal to or more than thereported buffer size, a UE according to the methodologies herein is ableto send a regular BSR message without waiting for the retransmit BSRtimer to expire. This robust mechanism enables the reduction ofcongestion in wireless networks and increases the user quality ofexperience (in particular by reducing application access and jitter)without greatly increasing signaling overhead as comparing to priorsolutions for reducing congestion causes by BSR messaging.

With reference to FIG. 7 in conjunction with the methodology of FIG. 8,at time T99, fifteen hundred (1500) bytes are now in the buffer of theUE. At time T100, a regular BSR message is transmitted from the UE tothe eNB. The BSR message is characterized as regular since it is not aperiodic message. The BSR message indicates that there are fifteenhundred (1500) bytes are in the buffer of the UE (i.e., fifteen hundred(1500) bytes available for transmission in the UL buffers of the UE). Attime T102, an additional three hundred (300) bytes are placed in the ULbuffers of the UE. At time T104, the eNB transmits a first grant messageto the UE; the UE receives from the eNB the first grant for five hundred(500) bytes. The buffer size being greater than the grant size, theperiodic BSR timer not yet having expired, and the total grant sizesince the last BSR (500 bytes) not being greater than or equal to thelast BSR size (1500 bytes) (FIG. 8: 816, 820, 822), at time T106, the UEtransmits a first data message of five hundred (500) bytes (FIG. 8: 824)and proceeds to wait for the next grant (FIG. 8: 814).

At time T107, the eNB transmits a second grant to the UE; the UEreceives from the eNB the second grant for five hundred (500) bytes. Thebuffer size being greater than the grant size, the periodic BSR timernot yet having expired, and the total grant size since the last BSR (500bytes) not being greater than or equal to the last BSR size (1500 bytes)(FIG. 8: 816, 820, 822), at time T108, the UE transmits a second datamessage of five hundred (500) bytes (FIG. 8: 824) and proceeds to waitfor the next grant (FIG. 8: 814). Note that the total grant size sincethe last BSR (1000 bytes=first grant 500 bytes+second grant 500 bytes)is not greater than or equal to the last BSR size (1500 bytes).

At time T109, the eNB transmits a third grant to the UE; the UE receivesfrom the eNB the third grant for five hundred (500) bytes.

At this point, the buffer size is greater than the grant size and theperiodic BSR timer has not yet expired but the total grant size sincethe last BSR (1500 bytes) is greater than or equal to the last BSR size(1500 bytes). Therefore, a regular BSR can be sent (FIG. 8: 816, 820,822, 826). The regular BSR message can be sent without waiting for theretransmisison timer expiration so that performance degradation isminimized and/or avoided.

At time T112, the eNB transmits a fourth grant to the UE; the UEreceives from the eNB the fourth grant for three hundred ten (310)bytes. The buffer size not being greater than the grant size (FIG. 8:816), at time T114, the UE transmits a fourth data message with a datasize equivalent to the grant of three hundred ten (310) bytes (FIG. 8:818).

FIG. 9 depicts a high-level block diagram of a computer suitable for usein performing functions described herein. In particular, this computeris suitable for implementation as a UE programmed with the methodologyof FIG. 6 or 8.

As depicted in FIG. 9, computer 900 includes a processor element 902(e.g., a central processing unit (CPU) and/or other suitableprocessor(s)) and a memory 904 (e.g., random access memory (RAM), readonly memory (ROM), and the like). The computer 900 also may include acooperating module/process 905 and/or various input/output devices 906(e.g., a user input device (such as a keyboard, a keypad, a mouse, andthe like), a user output device (such as a display, a speaker, and thelike), an input port, an output port, a receiver, a transmitter, andstorage devices (e.g., a tape drive, a floppy drive, a hard disk drive,a compact disk drive, and the like)).

It will be appreciated that the functions depicted and described hereinmay be implemented in software in conjunction with associated hardware(e.g., via implementation of software on one or more processors thataccess associated memory) and/or hardware (e.g., using a general purposecomputer, one or more application specific integrated circuits (ASIC),and/or any other hardware equivalents).

It will be appreciated that the functions depicted and described hereinmay be implemented in software for executing in conjunction with ageneral purpose computer (e.g., via execution by one or more processorsthat access associated memory) so as to implement a special purposecomputer, and/or may be implemented in hardware (e.g., using one or moreapplication specific integrated circuits (ASIC) and/or one or more otherhardware equivalents).

In one embodiment, the cooperating process 905 can be loaded into memory904 and executed by processor 902 to implement functions as discussedherein. Thus, cooperating process 905 (including associated datastructures) can be stored on a computer readable storage medium, e.g.,RAM memory, magnetic or optical drive or diskette, and the like.

It will be appreciated that computer 900 depicted in FIG. 9 provides ageneral architecture and functionality suitable for implementingfunctional elements described herein and/or portions of functionalelements described herein. For example, the computer 900 provides ageneral architecture and functionality suitable for implementing one ormore of one of the UEs 102, the eNBs 111, the MMEs 114 the SGWs 112 thePGW 113 the PCRF 115 the SGSN 122, and the Management System 160.

It is contemplated that some of the steps discussed herein as processes,procedures, or methods may be implemented within hardware, for example,as circuitry that cooperates with the processor to perform variousmethod steps. Portions of the functions/elements described herein may beimplemented as a computer program product wherein computer instructions,when processed by a computer, adapt the operation of the computer suchthat the methods and/or techniques described herein are invoked orotherwise provided. Instructions for invoking the inventive methods maybe stored in fixed or removable media, transmitted via a data stream ina broadcast or other signal bearing medium, and/or stored within amemory within a computing device operating according to theinstructions.

Although various embodiments which incorporate the teachings of thepresent invention have been shown and described in detail herein, thoseskilled in the art can readily devise many other varied embodiments thatstill incorporate these teachings.

What is claimed is:
 1. An apparatus comprising a memory device; and anassociated processor, the processor configured to transmit a bufferstatus report message when a reported buffer size in a last transmittedbuffer status report message is satisfied.
 2. The apparatus of claim 1wherein the processor is configured to store the reported buffer sizeassociated with the last transmitted buffer status report message; andtrack one or more grants of uplink resource; wherein the reported buffersize associated with the last transmitted buffer status report messageis satisfied based on the grants of uplink resource.
 3. The apparatus ofclaim 1 wherein the processor is configured to transmit the lasttransmitted buffer status report message.
 4. The apparatus of claim 1wherein the processor is configured to receive one or more grantmessages, the one or more grant messages each indicating a correspondinggrant size of the uplink resource; and accumulate a total grant sizebased on the corresponding grant size of the one or more grant messages.5. The apparatus of claim 4 wherein the processor is configured todetermine that the reported buffer size associated with the lasttransmitted buffer status report message is satisfied if the total grantsize is greater than or equal to the reported buffer size associatedwith the last transmitted buffer status report message.
 6. The apparatusof claim 1 wherein the processor is configured to determine that thereported buffer size associated with the last transmitted buffer statusreport message is satisfied when buffer size is greater than grant sizeof a first of the one or more grants of uplink resource, a periodicbuffer status report timer has not expired, and a total grant size ofthe one or more grants of uplink resource is greater than or equal tothe reported buffer size associated with the last transmitted bufferstatus report message.
 7. The apparatus of claim 1 wherein the apparatusis a user equipment.
 8. The apparatus of claim 1 wherein the processoris configured to transmit a data message in response to the one or moregrants of uplink resource.
 9. The apparatus of claim 8 wherein theprocessor is configured to adjust a size of the data message to accountfor transmission of the buffer status report message within a same grantof uplink resource.
 10. The apparatus of claim 1 wherein the processoris configured to transmit another buffer status report messageperiodically.
 11. The apparatus of claim 1 wherein the processor isconfigured to transmit another buffer status report message in responseto the one or more grants of uplink resource after expiry of a periodictimer.
 12. A method comprising: storing a reported buffer sizeassociated with a last transmitted buffer status report message;tracking one or more grants of uplink resource; and transmitting abuffer status report message when the reported buffer size associatedwith the last transmitted buffer status report message is satisfiedbased on the one or more grants of uplink resource.
 13. The method ofclaim 12 further comprising: transmitting the last transmitted bufferstatus report message.
 14. The method of claim 12 wherein tracking oneor more grants of uplink resource comprises: receiving one or more grantmessages, the one or more grant messages each indicating ancorresponding grant size of the uplink resource; and accumulating atotal grant size based on the corresponding grant size of the one ormore grant messages.
 15. The method of claim 14 further comprising:determining the reported buffer size associated with the lasttransmitted buffer status report message is satisfied if the total grantsize is greater than or equal to the reported buffer size associatedwith the last transmitted buffer status report message.
 16. The methodof claim 12 further comprising: determining if the reported buffer sizeassociated with the last transmitted buffer status report message issatisfied when buffer size is greater than grant size of a first of theone or more grants of uplink resource, a periodic buffer status reporttimer has not expired and a total grant size of the one or more grantsof uplink resource is greater than or equal to the reported buffer sizeassociated with the last transmitted buffer status report message. 17.The method of claim 12 wherein the method is performed by a userequipment.
 18. The method of claim 12 further comprising: transmitting adata message in response to the one or more grants of uplink resource.19. The method of claim 18 transmitting the data message comprises:transmitting the data message with a size of the data message adjustedto account for the transmitting of the buffer status report messagewithin a same grant of uplink resource.
 20. The method of claim 12further comprising: transmitting another buffer status report message inresponse to the grants of uplink resource after expiry of a periodictimer.